TOPIK I Grammar · Ch.1 Sentence Basics 03

TOPIK I Grammar · Ch.1 Sentence Basics 03

'이/가 vs 은/는' - The Choice Every Learner Asks About

This is one of the questions Korean learners ask most, and the honest answer is: you'll refine your feel for it over years. But for TOPIK I, two clear situations give you a dependable starting point.

Key point 이/가 puts the spotlight on who or what - new or important information. 은/는 sets the topic - "as for X" - for things already known or being contrasted. Form: 이/은 after a final consonant (batchim), 가/는 after a vowel.

How to use it

English has a rough parallel: a and the. "A man walked in. The man sat down." The first mention is new information; after that, he's known. Korean works with a similar feel: 남자가 들어왔어요 introduces him with 가 (new, spotlight), and once he's established, 그 남자는 앉았어요 continues with 는 (known topic). It is not a perfect match. Korean has no articles, and 은/는 can also show contrast. Still, your sense of "new" versus "already known" will guide you correctly most of the time.

The clearest test: questions and answers about "who" or "what." The neutral answer to 누가 왔어요? (= who came?) normally uses 이/가, because the whole point of the sentence is that new piece of information. And when you introduce yourself, use 는: 저는 마이클이에요 - "as for me, I'm Michael."

At a glance

After the noun	Spotlight 이/가	Topic 은/는
학생 (batchim)	학생이	학생은
친구 (vowel)	친구가	친구는
이름 (batchim)	이름이	이름은
저 (I, polite)	제가 - form changes!	저는
나 (I, casual)	내가 - form changes!	나는

Examples

제 이름은 마이클이에요. My name is Michael. - Introducing yourself sets the name as the topic: as for my name, ...

비가 와요. It's raining. - The rain is the new information, so 가.

동생은 키가 커요. My younger sibling is tall. - 은 sets the topic, and 가 spotlights what is actually big - the height.

Common mistakes

❌ 저가 학생이에요. → ⭕ 제가 학생이에요. 저 + 가 fuses into 제가, and 나 + 가 into 내가. These two common pronouns change shape - and they appear in almost every conversation, so this error is very visible.

❌ 누가 왔어요? - 마이클은 왔어요. → ⭕ 마이클이 왔어요. The question asks for new information, so the answer needs the spotlight particle. 마이클은 here sounds like a contrast: "Michael came (but someone else didn't)."

Quick check

Fill in each blank with 이, 가, 은, or 는.
1. A: 누가 학생이에요?  B: 제(    ) 학생이에요.
2. 저(    ) 한국 사람이 아니에요.
3. 언니는 커피를 마셔요. 저(    ) 차를 마셔요.

Show answers

1. 가 (answer to "who" - spotlight; 저 + 가 → 제가)   2. 는 (I am the topic)   3. 는 (contrast with 언니)

💡 Study tip - Don't try to master this in one day. For now, lock in just two habits: 저는 for introducing yourself, and 이/가 for answering "who?" or "what?" questions. These two situations cover most TOPIK I sentences.